The separating, shredding, mixing, pulverizing, sifting and sorting of material is a common and widespread agricultural and industrial application and practice. Such applications are to be found in the steel, glass, chemical, pharmaceutical, and food processing industries where liquid, semi-liquid, and liquid and solid product must be mixed and sifted, separated and sorted for transformation into a usable and valuable end product or commodity.
However, the above processes are applicable not only for large-scale industries but also for small scale concerns and businesses as well as individuals involved in activities such as building, remodeling, renovating, landscaping, gardening and general outside work. Thus, in situations such as landscaping, preparing a garden or starting a lawn as part of a new housing project, a primary task is soil preparation. The soil must be screened and sifted in order to separate and remove the usable and valuable soil—topsoil or loam, for example—from the unwanted and unusable soil and other debris found therein. The other debris may include such items as stones, rocks, gravel, roots, branches, and bulk waste, trash, and rubbish that has not been broken down or decomposed.
Some common ways of sifting and sorting through soil material include simply walking the parcel and manually removing the clumps of debris, using a shovel or other implement to manually sift and sort through the soil, and placing a flat mesh screen on a wheelbarrow and then placing loads of soil on the screen for separating the unusable and unwanted debris from the valuable soil. These methods are time consuming and labor intensive, and produce uneven results as far as the quality of the soil screened and sorted.
The prior art discloses a wide variety of devices for separating, sorting, spreading, shredding and mixing material to obtain a desirable end product.
For example, the Raney et al. patent (U.S. Pat. No. 3,025,067) discloses a flail beater unit attached to the rear of a manure spreader unit. Manure is brought to the flail beater unit by a conveyor whereupon the manure is beaten and spread by individual flails rotating on a center shaft.
The Skretting patent (U.S. Pat. No. 4,303,508) discloses a screening device wherein an externally slotted screen drum is enclosed within a housing so that primarily cellulose-type material passes through the slots when moving from the inlet to the outlet.
The Svehaug patent (U.S. Pat. No. 4,426,289) discloses a liquid-solid screen separator that includes a slurry screening assembly mounted within a rotatable housing for screening the slurry, a compression roller freely rotatable therein for further compressing the material, and an augur for moving the material through the separator.
The Palus et al. patent (U.S. Pat. No. 4,767,218) discloses a vat for mixing delicate material and which includes a carriage assembly linearly movable on a beam member, and pendent from the carriage assembly are mixing paddles having blades that can be selectively angled for achieving maximum mixing results.
The Thompson patent (U.S. Pat. No. 4,885,012) discloses a conveyance apparatus for moving granular matter, and includes a container having inlet and outlet conduit, a rotary screen assembly within the housing, and a rotary valve for continuously moving the material.
The Lundell patent (U.S. Pat. No. 4,960,247) discloses a compost shredder wherein compost is fed into the hopper for shredding by hammers pivotally mounted to a shaft that extends through a drum that receives the compost from the hopper.
The Byers patent (U.S. Pat. No. 5,118,414) discloses a screening device for removing unwanted material from water, and includes a plurality of upright annular discs having peripheral teeth for catching and directing unwanted material to a collection zone.
Nonetheless, despite the ingenuity of the above devices, there remains a need for a simple, portable screening device for small business concerns, homeowners and individuals for quickly and efficiently screening and sorting unwanted material from usable soil.